Vehicles are conventionally provided with a wiper device attached to the windshield to wipe off rain, splashes from a preceding vehicle, etc. in order to provide the driver with an optimum field of vision. The wiper device has a wiper arm whose oscillation is controlled by a wiper-driving device and a wiper blade abutting the windshield is mounted on a tip end of the wiper arm. The wiper arm on which the wiper blade is mounted performs a reciprocating motion, so that wiping of the windshield is performed. A link mechanism changes a rotational motion of a motor to a reciprocating motion and thus the wiper arm performs a wiping operation.
Because the wiper arm is required to perform a reciprocating motion, a more efficient and highly-functional wiper device is obtained in case that the motor generating a driving force for the reciprocating motion performs switching between the forward rotation and the reverse rotation, which makes the link mechanism for causing the reciprocating motion unnecessary, rather than in case that the reciprocating motion is implemented through the link mechanism by rotating the motor in only one direction. Therefore, the number of wiper devices which cause the wiper arm to reciprocate by switching the rotation of the motor between the forward rotation and the reverse rotation has recently increased (for example, see Patent Literature 1).